Greenhouse gas emissions from croplands of China

China possesses cropland of 1.33 million km 2. Cultivation of the cropland not only altered the biogeochemical cycles of carbon (C) and nitrogen (N) in the agroecosystems but also affected global climate. The impacts of agroecosystems on global climate attribute to emissions of three greenhouse gases, namely carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O)

Effect of mineral-based amendments on rice (Oryza sativa L.) growth and cadmium content in plant and Polluted soil

Agricultural soils can be contaminated by industrial activities such as mining and smelting. Contamination with cadmium (Cd) can significantly exceed average background values, which can lead to uptake by rice plant and even harm to humans through food chain. In Hunan province, southern China, rice (Oryza sativa L.) is the main cereal, and human exposure to metallic contaminants through rice pathway is of particular interest. Shortage of land for rice growing means that contaminated agricultural soil is still cultivated for rice in Hunan. In the present work, a field experiment was undertaken to remediate Cd-contaminated paddy soil with three mineral amendments, namely sepiolite, bone char, and a silicon-based product (normally used as fertilizer). Average Cd concentration in the paddy soil was 2.85 mg/kg, significantly exceeding Chinese soil quality standards of China. Cd content was 0.59 mg/kg in sepiolite, 0.28 mg/kg in bone char, and 0.44 mg/kg in silicon fertilizer, respectively. Distribution fractions of Cd in soil followed the order of exchangeable (FI) > organic matter-bound (FIII) > residual (FIV) > oxide-bound (FII) without treatment, while exchangeable (FI) > residual (FIV) > organic matter-bound (FIII) > oxide-bound (FII) after treatment. With addition of three amendments, soil pH values and rice growth such as plant height and ripening rate increased. Concentrations of Cd in the rice plant (straw, husk, and unpolished rice) decreased after treatment. However, among three amendments, only the bone char addition reduced Cd accumulation in the rice plant below the Chinese standard value (0.2 mg/kg) and in the husk to below the Chinese feed hygiene standard for food (0.5 mg/kg)

Response of Vicia faba L. to metal toxicity on mine tailing substrate:Geochemical and morphological changes in leaf and root

Vicia faba L. seeds were grown in a pot experiment on soil, mine tailings, and a mixture of both to mimic field situations in cultivated contaminated areas near mining sites. Metals in the substrates and their translocation in root, stem and leaf tissues were investigated, including morphological responses of plants growing on mine tailings. Metal concentration � and generally bioaccumulation � was in the order: roots > leaves > stems, except Pb and Cd. Translocation was most significant for Zn and Cd, but limited for Pb. Metal concentration in root and leaf was not proportional to that in the substrates, unexpectedly the minimum being observed in the mixed substrate whilst plant growth was retarded by 20% (38% on tailings). Calcium, pH, organic matter and phosphorus were the main influencing factors for metal translocation. The ultrastructure of V. faba L. cells changed a lot in the mine tailings group: root cell walls were thickened with electron dense Pb, Zn and C particles; in chloroplasts, the number of plastoglobuli increased, whereas the thylakoids were swollen and their number decreased in grana. Finally, needle-shaped crystalline concretions made of Ca and P, with Zn content, were formed in the apoplast of the plants. The stratagems of V. faba L. undergoing high concentrations of toxic metals in carbonate substrate, suggest root cell wall thickening to decrease uptake of toxic metals, a possible control of metal transport from roots to leaves by synthesizing phytochelators�toxic metal complexes, and finally a control of exceeded Ca and metal concentration in leaves by crystal P formation as ultimate response to stress defense. The geochemical factors influencing metal availability, guaranty a reduction of metal content in plant growing on mixed tailing/soil substrate as far as carbonate are not completely dissolved

Rapid assembly of colorless antimicrobial and anti-odor coatings from polyphenols and silver

This work was partially supported by the Japan Society for the Promotion of Science (JSPS) KAKENHI (Grant No. 20F20373 and 20H02581), the Japan Science and Technology Agency (JST) through the Precursory Research for Embryonic Science and Technology (PRESTO) grant number JPMJPR21N4, and UTokyo-Tsinghua collaborative research fund. JJR acknowledges JSPS for the postdoctoral fellowship for research in Japan (P20373). We acknowledge TokudAw Inc for the silk masks.The development of antimicrobial fabrics and textiles that can sustainably inhibit a broad spectrum of microbes is crucial for protecting against pathogens in various environments. However, engineering antimicrobial textiles is challenging due to issues with discoloration and inhibited breathability, the use of harmful or harsh reagents and synthesis conditions, and complex and/or time-consuming processing. Herein, we develop a facile and rapid approach to deposit antimicrobial coatings using universally adherent plant polyphenols and antimicrobial silver ions. Importantly, the coatings are colorless, thin (< 10 nm), rapidly assembled (< 20 min), and can be deposited via immersion or spraying. We demonstrate that these metal-phenolic coatings on textiles can inhibit lipid-enveloped viruses over one thousand times more efficiently than coatings composed of other metal ions, while maintaining their efficacy even after 5 washes. Moreover, the coatings also inhibit Gram positive and negative bacteria, and fungi, and can prevent odors on clothes for at least 10 washes. Collectively, the ease of synthesis, use of simple and safe precursors, and amenability to at-home and industrial application suggests that the coatings will find practical application in various settings.Peer reviewe